Titanium and zirconium organic compounds



TITANIUM AND ZIRCONIUM ORGANIC COMPOUNDS Daniel Kaufman, Metuchen, N.J.,assignor to National Lead Company, New York, N.Y., a corporation of NewJersey No Drawing. Application August 26, 1953 Serial No. 757,184

9 Claims. (Cl. 260-4293) This invention relates in general to titaniumand Zirconium organic compounds and more specifically to titanium-carbonor zirconium-carbon bonded compounds.

A number of metal-carbon bonded compounds have previously been preparedand among these are bis-cyclo pentadienyl titanium andbis-cyclopentadienyl titanium dihalide and zirconium dihalide. Thelatter compound, i.e. the dihalide of both titanium and zirconium andits method of preparation is more fully described and claimed inco-pending application Serial No. 443,956, filed July 16, 1954, byDaniel F. Herman, said application being assigned to the same assigneeas the instant application.

Such compounds are of interest as catalytic agents and as reagents invarious organic reactions for the preparation of other organiccompounds. It is desirable therefore to produce derivatives of suchcompounds so that these compounds may have wider applications in variousorganic systems.

An object of the instant invention therefore is to produce derivativesof bis-cyclopentadienyl titanium and zirconium compounds. A furtherobject is to produce derivatives of bis-cyclopentadienyl titanium andzirconium dihalide. Another object is to produce derivatives whichwillhave applications other than those of the bis-cyclopentadienyl titaniumand zirconium dihalides themselves. A still further object is to producederivatives which under certain conditions are more reactive than eitherbis-cyclopentadienyl titanium or zirconium dihalide. A further object isto provide a method for producing derivatives of bis-cyclopentadienyltitanium and zirconium dihalide. These and other objects will becomemore apparent from the following more complete description of theinstant invention.

Broadly, this invention contemplates a compound comprising a derivativeof bis-cyclopentadienyl metal dihalide, said metal selected from thegroup consisting of titanium and zirconium, said dihalide selected fromthegroup consisting of fluorine, chlorine, bromine and iodine, saidderivative containing one cyclopentadienyl group, one aliphatic groupand 2 halogens attached to each metal atom, said aliphatic group being a5 membered carbon ring and containing from 2 to 4 halogens selected fromthe group consisting of chlorine, bromine and iodine, said halogensattached to said ring.

This invention further contemplates a method for the preparation ofderivatives of bis-cyclopentadienyl metal dihalide, said metal selectedfrom the group consisting of titanium and zirconium, said dihalideselected from the group consisting of fluorine, chlorine, bromine andiodine, which comprises reacting bis-cyclopentadienyl metal di halidewith a halogen selected from the group consisting of chlorine, bromineand iodine. A preferred embodiment of the instant invention is tosuspend the bis-cyclopentadienyl metal dihalide in an inert solvent andreact the suspension with the halogen.

Bis-cyclopentadienyl titanium or zirconium dihalide States PatentPatented Jan. 26,1960

o 2 is not very soluble in most inert solvents and therefore it isconvenient, but not necessary, to form a suspension. Most any inertsolvent may be employed and among the most readily available are CClCHCl hexane, cyclohexane, petroleum ether and tetrachloroethane.

The reaction is simple and straightforward. The halogen is merelyreacted with the bis-cyclopentadienyl metal dihalide and the derivativesare formed. Usually a large excess of the halogen is used to permit amore complete reaction to take place. The reaction is usually run underatmospheric pressure but may be rununder' pressure if desired. Thereaction is usually carried out at room temperature, however, thetemperature employed is dependent upon either the solvent or pressureused.

In carrying out the reaction between the bis-cyclopentadienyl titaniumor zirconium dihalide and the halogen, two derivatives may be formed.Apparently only one of the cyclopentadienyl rings is attached and thehalogen is attached thereto in multiples of two. The first derivativewhich is formed, and is isolable if desired, is cyclopentadienyl(dihalocyclopentenyl) metal dihalide. This derivative is then furtherhalogenated if desired to produce another isolable derivative whichcontains 4 halogens, that is, cyclopentadienyl (tetrahalocyclopentanyl)metal dihalide.

As bis-cyclopentadienyl metal dihalide is reacted with chlorine, bromineor iodine, the derivatives are formed stepwise, i.e. cyclopentadienyl(dihalocyclopentenyl) metal dihalide is formed first and then as morehalogen is added cyclopentadienyl (tetrahalocyolopentanyl) metaldihalide is produced. The reaction maybe stopped at anytime if desiredand the particular derivatives produced are directly dependent upon theamount of chlorine, bromine or iodine added. Since chlorine is mostconveniently added as a gas by bubbling the gas through the suspension,a large excess is usually employed to obtain sufficient contact betweenthe chlorine gas added and the bis-cyclopentadienyl metal dihalideemployed. Both bromine and iodine are most conveniently employed insolution and therefore a much better contact is obtained between thebromine or iodine added and the hiscyclopentadienyl metal halideemployed and only a slight excess over the theoretical quantity-ofbromine or iodine is rgquired to produce either one of thederivativesdesire Both of these derivatives contain one cyclopentadienyl group andone aliphatic 5 membered carbon ring attached to each metal atom. Bothderivatives also have 2 halogens attached to each metal atom. Inaddition these derivatives contain either 2 or 4 halogens selected fromthe group consisting of chlorine, bromine and iodine,

said halogens are attached to the aliphatic 5 membered carbon ring.

In carrying out the process of this invention, any of thebis-cyclopentadienyl titanium or zirconium dihalides may be used. All ofthe titanium dihalide compounds are colored solids which vary from ayellow color for the difluoride to a deep red for the diiodide. Thedichloride and dibromide lie in between as shades of red. All of thezirconium dihalide salts are white. Any of these dihalides are reactedwith a halogen selected fromthe group consisting of chlorine, bromineandiodine and the titanium derivatives formed are all solids varying incolor in various shades of orange while the solids are white forzirconium derivatives.

In order to describe more fully the instant invention, the followingexamples are presented.

Example 1 0.69 gram of bis-cyclopentadienyl titanium dichloride wasdissolved in ml. hot C01 Chlorine gas was 0.6 gram (ifbis-'cyclopentadienyl titanium dichloride and 2 "ml. "liquid brominewere added to 200 ml. CCL; and 'the mixture was allowed to standovernight in a refrigerator at C. The mixture was then heated to boiling(in a hot plate "to remove the bulk'of the excess bromine. The solutionwas cooled and filtered prior to vacuum stripping. 1.20 grams ofyellowmrahge crystals of cyclopentadienyl tetrabromocyclopentanyltitanium dichloride were recovered. Theoretical Ti=8.44%;'foundTi"=8.21%.

It should be noted that the second derivative, 'i.'e. cyclopentadie'nyltetrabromocyclopentanyl titanium dichloride, was produced instead'of thefirst, i.e. cyclope'ntadienyl dibromocyclopentenyl titaniumdichloridesince an excess of 'bromine was employed. If the amount orbromine were limited to substantially the theoretical amount to formcyclopentadienyl dibr'o'rhocyclopfitenyl titanium dibromide,'only thefirst derivative would have been formed.

Example 3 0.15 gram of bis-cyclopentadienyl iir'c'onium dichltiride wasplaced in 'a flask with 250 ml. CCld and =chlb ritie gas wasbubbled'through the mixture for l hour at the rate'or50 ml./min. Theflask was stopperedand pla'ced in "a refrigerator overnight. Upon'filteri'n g; a white c'a'rnphorac'eous smelling solid weighingv 0.1gram was obtained afterdrying under vacuum for --2 hours. Thecyclopentadienyl tetrachlorocyclopentanyl Zirconium dichloride wasidentified by comparison of its infrared spectra "withthe analogoustitanium compound.

'It'shbuld be 'not'ed that the second derivative,-recyclepentadi'enyltetrachlorocyclopentanyl -zirconium dichlo-,

ride 'was'forrned insteadof' the first derivative. Itfshduld be furthernoted that this example diiiers from tliat of Example 1 in the amountsotreagents-used. The amount of b'is-cyclopentadienyl zirc oniu'mdichloride employed was cohside'rably les s than the amount ofbis-cyclbpenta dienyl titanium dichloride used in Example 1 while theamoun er meriaenreaw s the same, therefore, the ratio of chlorine totlie -bis cyclopentadienyl-metal dichloride wasmuch greater in Example3than inExample 1 which results 'in theformationof the secondderivativei'nsteadof the first.

Example 4 pered and placed in a refrigerator overnight. The solution"was vacuum stripped-t0 removethe solventand excess chlorineleavinganorange colored solid. The

product was identified as cyclopentadienyl tetrachlorocyclopentanyltitanium dibromide.

Example 6 0.5 gram of bis-cyclopentadienyl titanium diiodide and 1.0gram of L was mixed in a flask with 50 ml. of CCl.;. The mixture washeated for one hour under gentle refiuxing conditions and was cooled andpermitted to stand overnight. The reactionmixture was stripped of thesolvent and the excess iodine was siiblimed off the product. Thematerial was recrystallized 'fromCCl; and was identified ascyclopentadienyl tetraiodocycldpentanyl titanium diiodide.

Example 7 0.4 gram or bis cyclopentadienyl titanium difluoride wasadmixed with 2 ml. liquid bromine and 200 ml. of CCl The mixture wasallowed to stand overnight in a refrigerator at 0 'C. The rnixtu'revvasthen heated on ah'ot plate to remove the'bulk of the excess b'r'omine.The mixture was cooled and filtered prior to vacuum stripping. Theyellow-orange crystals obtained were identified as cyclopentadie nyltetrabromocyclopentahyl titanium diiluo'ride.

Example 8 015 gram of bis-cyclopentadienyl titanium dibrornide and 2 ml.of liquid bromine were added to 200 ml. of @Clgand the mixture wasallowed to'stand overnight at 0 C. Themixture was then heated to removethe bulk ofth'e bromine. The solution was cooled and filtered prior tovacuum stripping. The orange-colored crystals were identified ascyclopentadienyl tetrabromocyclopentanyl titanium dibromide and had thefollowing analysis.

C H Ti Br Theory 18. 2 1. 5 7. 3 72.' 8 Found l8. 0 2. 5 6. 5 '71. 2

"From the above description and by the 'examplesp'resented, a new typeof derivative of bis-cyclopenta'dienyl titanium 'or "zirconium dihalidehas beenproduced. The derivatives formed contain an entirely new andnovel typ'e'of bond, that is, a stable aliphatic carbon-metal bond fdrboththe titanium and zirconium'c'crnpounds'. Such a newbo'nd is far morereactive than'the cyclopntadienyl metal bond and therefore is moreuseful in free radical type 'reactions in the production 'of'variens nlrners and in other 'organic' systems.

One particular type of reaction which"utiliiesftheproduct of the instantinvention is in the polymerization "of styrene which uses the instantproduct as a catalyst. Styrene is'polymerized as follows: v

005 gram of the cyclopentadienyl dichlorocyclopentenyl titaniumdichloride prepared in Example 1 was dissolved in 5 0 grams of aninhibitor-freestyrene. This solution was then added under nitrogenatmosphere with stirring'to 100 ml. H O containing'l gram of ethylsulfonate. which is a surface active agent, and 010159 gram ofta rtaricacid. After 2 /2 hours heating at -'-9 '0 C. a white 'emulsion wasformed which was addedto 500' ml. methyl alcohol to precipitate a finelydivided white'fpolystyrene which was filtered, dried and recovered. Thispolymer was tested and found to be superior to known grades ofpolystyrene in that thepolymcr prepared; by the catalyst ofthisinvention was tougher and had a higher molecular weight. The methodwas repeated using cyclopentadi enyl tetrabromocyclopentanyl titaniumdichloride prepared in Example 2 and a similar. polystyrenewas-obtained.

his applicationis a-continuation-in-part of Serial No. 540,167 filedOctober- 12, 1955, now abandoned.

While this invention has been described and illustrated by the examplesshown, it is'not intended to be strictly 5 limited thereto, and othervariations and modifications may be employed within the scope of thefollowing claims.

I claim:

1. A compound comprising a derivative of bis-cyclopentadienyl metaldihalide, said metal selected from the group consisting of titanium andzirconium, said dihalide selected from the group consisting of fluorine,chlorine, bromine and iodine, said derivative having onecyclopentadienyl group, one aliphatic group and two halogens directlyattached to each metal atom, said aliphatic group selected from thegroup consisting of dihalocyclopentenyl and tetrahalocyclopentanyl.

2. Compound according to claim 1 in which 2 chlorines are attached toeach metal atom.

3. Compound according to claim 1 in which 2 bromines are attached toeach metal atom.

4. Compound according to claim 1 in which 2 iodines are attached to eachmetal atom.

5. Compound according to claim 1 in which 2 fluorines are attached toeach metal atom.

6. Compound according to claim 1 in which the metal in said compound istitanium.

7. Compound according to claim 1 in which the metal in said compound iszirconium.

8. Compound according to claim 1 in which said aliphatic group isdihalocyclopentenyl.

9. Compound according to claim 1 in which said aliphatic group istetrahalocyclopentanyl.

No references cited.

1. A COMPOUND COMPRISING A DERIVATIVE OF BIS-CYCLOPENTADIENYL METALDIHALIDE, SAID METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM ANDZIRCONIUM, SAID DIHALIDE SELECTED FROM THE GROUP CONSISTING OF FLUORINE,CHLORINE, BROMINE AND IODINE, SAID DERIVATIVE HAVING ONECYCLOPENTADIENYL GROUP, ONE ALIPHATIC GROUP AND TWO HALOGENS DIRECTLYATTACHED TO EACH METAL ATOM, SAID ALIPHATIC GROUP SELECTED FROM THEGROUP CONSISTING OF DIHALOCYCLOPENTENYL AND TETRAHALOCYCLOPENTANYL.